a. Field of Invention
This invention relates to tricyclic acetic acid derivatives, to their preparation and use, and to intermediates used for their preparation.
More specifically, this invention relates to tricyclic acetic acid derivatives in which the tricyclic portion thereof is characterized by having an indole portion fused to a cyclohexane ring. Still more specifically, the compounds of this invention are characterized as derivatives of the following tricyclic acetic acid system: ##STR1## 2,3,4,9-tetrahydro-1H-carbazole-1-acetic acid in which the carbons at the 1-, 4-, 7- and 8- positions are further substituted.
The tricyclic acetic acid compounds of this invention possess useful pharmacologic properties; for instance, they exhibit analgesic and antiinflammatory activity at dose levels which do not elicit undesirable side effects. The foregoing combination of attributes renders the compounds of this invention useful for the treatment of inflammatory conditions and of pain.
b. Prior Art
The closest prior art to the present invention is:
Asselin et al. U.S. Pat. No. 4,057,559. Asselin discloses analgesic and antiinflammatory agents having the same heterocyclic ring system as the present invention but without the substituents of the present invention.
Demerson et al. U.S. Pat. No. 3,939,178 discloses 1,3,4,9-tetrahydropyrano[3,4-b]indoles and 1,3,4,9-tetrahydrothiopyrano[3,4-b]indoles having analgesic and antiinflammatory activity. Related U.S. Pat. Nos. are 3,974,179 and 3,843,681.
Boehringer Mannheim European Patent 42593 generically discloses starting materials useful for producing cardiotonic and beta-blocking agents. The starting materials include 1,2,3,4-tetrahydrocarbazoles with substituents selected from the broad group including hydrogen, carboxy, lower alkyl and lower alkenyl. The starting materials are in each case also substituted with a reactive group which distinguishes them from the compounds of the present invention.
Further removed, related patents that include tetrahydrocarbazoleacetic acid derivatives useful as analgesic and antiinflammatory agents are U.S. Pat. Nos. 4,234,487; 4,264,500; 4,193,923; 4,158,007; 4,146,542; 3,896,145 and 3,824,314; Japanese Patent No. J51032556; Netherland Patent NL No. 7,100,213 and Great Britian Pat. No. GB 1385620.